Producing Electricity through Condensation

Many interesting scientific discoveries have come from unexpected sources. Last year it was discovered at MIT that when water droplets leap from a superhydrophobic material, they can gain an electrical charge. Now MIT researchers have found a way to use this phenomenon to produce useable electricity.

Superhydrophobic materials are characterized by the fact that water hates to touch them, which has made them interesting for use in condensers. Water will still condense onto the hydrophobic material, and by leaping off of it, frees up space for more water to condense. When the researchers found that these leaping droplets will be charged, they added oppositely charged plates to condensers, to improve efficiency. By making the plate superhydrophilic instead, and connecting it to the superhydrophobic plate, the MIT researchers found they had created an electrical circuit.

So far tests have only produced 15 picowatts of power per square centimeter, but the researchers believe the device could be easily tuned to 1 microwatt per square centimeter, which is comparable to other devices that harvest ambient energy. While that is not much power, the remote systems that would be powered by this technology, do not necessarily need much.